Twenty-five years ago educational services for children with disabilities were frequently fragmented, underfunded, highly segregated, and unreliable. Public schools were often ill prepared and unwilling to provide special and necessary services to children with disabilities. Over the past two decades, efforts to provide an appropriate education for children with disabilities in America—through a series of state statutes, federal court cases, and federal laws—have led to the development of a large special education system to address the needs of these children. This journal issue focuses on the development of that special education system and examines its components, its strengths and weaknesses, and the areas in which improvement is needed. This Child Indicators article examines some of the key federal statistics on the provision of special education services for children with disabilities.

Statistics have played a part in shaping special education policy. A highlight of congressional hearings in the 1970s was the finding that 2.5 million children with disabilities in this country were not receiving an education appropriate to their needs, while almost 2 million others were receiving no education at all.1 As described by Martin and Martin in this journal issue, congressional response to such statistical evidence of underservice of the disabled included passage of Public Law 94-142, the Education of All Handicapped Children Act, which required that all students with disabilities receive a free public education appropriately tailored to their individual needs. A key element of this statute and its successors was that federal funding be provided to states for special education services based on state reports of the number of students with disabilities receiving special education and related services. This and other aspects of federal legislation have fostered the development of a data collection system to monitor the provision of special education services to disabled students by local and state educational agencies.

This article examines data collected by the federal Office of Special Education Programs (OSEP) on the identification and classification of special education students. These data are used throughout this journal issue, but a key question raised in this article is whether these data can be used to determine if the special education system is adequately and appropriately serving the nation's population of disabled children. The analysis suggests that the OSEP count data, by themselves, do not indicate how many children have disabilities and what types of disabilities they have; and although the data quantify the number of children receiving services, they cannot be used to evaluate whether the services received are appropriate for those children's needs.

The federal data do, however, show large variations in the numbers and proportions of children who are served in special education programs over time and across jurisdictions. OSEP data indicate a large increase in the number of children served in special education programs since the 1976–77 school year. Much of the increase appears to be the result of an increase in the number of children classified as having specific learning disabilities, a classification that is not well defined and is under considerable debate. Despite the overall growth trend, the proportion of children who are in special education varies by state, from 5% of children in special education in Hawaii to 11% in Massachusetts. In addition, different states use different classification systems to describe children in special education programs. Because of these differences, population-based data on the prevalence of disabilities among children would be helpful in determining the actual number of children who might benefit from special education services. The prevalence data could be compared with the OSEP count data to assess in gross terms the adequacy of special education services delivered to children with disabilities. But because of methodological problems, available national surveys do not provide reliable information on the prevalence of different conditions.